Electronic devices that include electronic components often generate heat during normal operation. Although some amount of heat build up is acceptable, the electronic devices perform optimally when excess heat is removed from the device.
One method used to remove heat from electronic devices is to have a fan blow air over the surface of the heat-generating components to remove heat to the ambient environment. A further way of removing heat is to use a heat sink or the like to remove heat from the electronic device. Although heat sinks are able to remove heat by themselves, heat sinks remove a significantly greater amount of heat when coupled with a fan to increase air flow through the fins of the heat sink.
One problem associated with fans is the amount of air flow generated by the fan. The greater the heat load, the greater the amount of air flow is required to remove heat from the device. This is true whether or not a heat sink is associated with the fan. However, the heat sink becomes more compact as the heat load increases. Consequently the pressure drop increases, thereby reducing the air moving capacity of the fan.
A second problem associated with fans is the noise that they generate. Various methods have been attempted to minimize the amount of excess noise that fans add to a device. Such methods include elective choice of impeller geometry, utilizing a variable-speed fan, applying sound absorbing material around the fan and the duct housing, and locating the fan remotely from the device. These techniques have been inadequate in reducing noise for high airflow applications.
Consequently, a need exists for a low-noise, high-performance fan that is effective in producing an adequate air flow in electronic devices while not adding significant noise to the device.